Panniculitis is a term used to describe a rare condition in which the layer of fat under the skin becomes inflamed. While this condition may be caused by an infectious agent such as bacteria, fungi or other microorganisms, the term sterile nodular panniculitis is used when the inflammation does not involve any infectious agents. Dachshunds and Weimaraners seem to be predisposed to this condition.
With sterile nodular panniculitis, single or multiple nodules will appear under the skin. The head, neck, back and trunk are the most commonly affected areas. These nodules can rupture and drain an oily discharge that may be clear, bloody or yellowish-brown. Dogs may also present with other symptoms such as fever, anorexia and lethargy.
Diagnosis is achieved with skin biopsies along with cultures to rule out infection.
Pets are always evaluated for any evidence of predisposing disease like pancreatititis or autoimmune conditions, as well as any recent drug administrations. The majority of the cases however are classified as idiopathic, meaning that no underlying cause can be identified.
Treating infection or underlying disease is paramount in non-idiopathic forms of the disease. In idiopathic forms most pets are treated with immunosuppressive drugs, while supplementation with oral Vitamin E may also be helpful. In the case of a solitary nodule, surgical excision may be advised.